I have one of those.
I think that I played the last few hours of Legend of Legaia on it (which I did enjoy).
Overall, I'm not particularly impressed with it though. I guess it's alright for PS1 games (if you can't be troubled to use a PSP for some reason

), but I can't see playing PS2 era games on that tiny of a screen. The screen isn't as sharp as I'd like either (seemed a little grainy), but probably as good as you could expect for the size and time it was released.
Can't remember how hard it is to read text on the thing.
Also, The controller feels a little cheap to me...and if it ever breaks, you are pretty much out the whole unit (unless you are handy with modding).
Also, mine has a stuck red-pixel.
But I think I only paid $20 for it. It was a fair deal for a gaming oddity.
...just another lost soul...